Hybrid torque bar

ABSTRACT

A hybrid torque bar for a brake assembly may comprise a base portion, a pin extending from a first end of the base portion, and a rail extending between the first end of the base portion and a second end of the base portion opposite the first end. The base portion may be formed using a first manufacturing process. At least one of the pin or the rail may formed using a second manufacturing process. The second manufacturing process may comprise an additive manufacturing technique.

FIELD

The present disclosure relates to brake systems, and more specifically,to torque bars for aircraft brake systems.

BACKGROUND

Torque bars are typically used in aircraft wheel and brake assemblies tocouple the wheels to the rotors of the brake assembly. Torque barstypically extend from an inner surface of the wheel in a directionparallel to the rotational axis of the wheel, and are subject todeflection and vibration. The geometries of torque bars haveconventionally been limited by conventional, subtractive manufacturingtechniques. These geometric limitations can limit the characteristics ofthe torque bars, such as, for example, the ability to resist deflectionand wear. Additionally, machining the torque bar from a single piece ofmetal tends to generate a large amount of waste material.

SUMMARY

In accordance with various embodiments, the present disclosure providesa hybrid torque bar for a brake assembly. The hybrid torque bar maycomprise a base portion, a pin extending from a first end of the baseportion, and a first rail extending between the first end of the baseportion and a second end of the base portion opposite the first end. Aninterior portion of at least one of the pin or the first rail maycomprise a first metal alloy. An exterior portion of the at least one ofthe pin or the first rail may comprise a second metal alloy. Anintermediate portion of the at least one of the pin or the first railmay extend between the interior portion and the exterior portion.

In various embodiments, the intermediate portion may form a gradienttransition between the first metal alloy and the second metal alloy. Thegradient transition may include a percent by weight of a wear resistantcoating material defined by a smooth function of position along thegradient transition. The wear resistant coating material may comprise atleast one of a metal carbide, a nickel-alloy, or a nickel-based superalloy.

In various embodiments, a second rail may extend between the first endof the base portion and the second end of the base portion. A crossmember may extend between the first rail and the second rail. The crossmember may define an opening.

In various embodiments, a first portion of the first rail extends in afirst direction, and a second portion of the first rail extends in asecond direction opposite the first direction. An attachment flange mayextend from the base portion in the first direction. In variousembodiments, the first rail may define a hollow portion.

Also disclosed herein, in accordance with various embodiments, is awheel assembly. The wheel assembly may comprise a wheel and a hybridtorque bar coupled to the wheel. The hybrid torque bar may comprise abase portion, a pin extending from a first end of the base portion, anda rail extending between the first end of the base portion and a secondend of the base portion opposite the first end. An interior portion ofat least one of the pin or the rail may comprise a first metal alloy. Anexterior portion of the at least one of the pin or the rail may comprisea second metal alloy. An intermediate portion of the at least one of thepin or the rail may extend between the interior portion and the exteriorportion.

In various embodiments, the wheel may comprise an inboard wheel half andan outboard wheel half. The pin may be located in a receptacle definedby the inboard wheel half.

In various embodiments, the first metal alloy may comprise a firstpercentage by weight of a wear resistant coating material, the secondmetal alloy may comprise a second percentage by weight of the wearresistant coating material, and the intermediate portion may comprise anincreasing percentage by weight of the wear resistant coating material.In various embodiments, the wear resistant coating material may comprisea metal carbide, a nickel alloy, or a nickel-based super alloy.

Also disclosed herein, in accordance with various embodiments, is amethod of making a hybrid torque bar for a wheel assembly. The methodmay comprise forming a base portion using a first manufacturing process,forming a pin extending from a first end of the base portion, forming anattachment flange extending from the base portion, and forming a railextending between the first end of the base portion and a second end ofthe base portion opposite the first end. A least one of the forming theattachment flange, the forming the pin, or the forming the rail maycomprise using a second manufacturing process, the second manufacturingprocess comprising an additive manufacturing technique.

In various embodiments, the first manufacturing process comprises atleast one of forging, extrusion, casting, machining, stamping, orsubtractive manufacturing.

In various embodiments, the method may further comprise forming at leastone of the attachment flange, the pin, or the rail comprising a coatinglocated at an exterior of the at least one of the attachment flange, thepin, or the rail. Forming the at least one of the attachment flange, thepin, or the rail comprising the coating may comprise forming an interiorportion of the at least one of the attachment flange, the pin, or therail using a first metal alloy, forming an exterior portion of the atleast one of the attachment flange, the pin, or the rail using a secondmetal alloy, and forming a gradient transition extending between theinterior portion and the exterior portion.

In various embodiments, the first metal alloy may comprise a firstpercentage by weight of a wear resistant coating material, the secondmetal alloy may comprise a second percentage by weight of the wearresistant coating material, and the gradient transition may comprise anincreasing percentage by weight of the wear resistant coating material.In various embodiments, the wear resistant coating material may compriseat least one of a metal carbide, a nickel alloy, or a nickel-based superalloy.

In various embodiments, the method may further comprise forming thegradient transition including a percent by weight of the wear resistantcoating material defined by a smooth function of position along thegradient transition. The smooth function of position may comprise atleast one a linear function, a logarithmic function, an exponentialfunction, or a quadratic function. In various embodiments, the methodmay further comprise forming the coating extending over, at least aportion of, a surface of the base portion.

The forgoing features and elements may be combined in variouscombinations without exclusivity, unless expressly indicated hereinotherwise. These features and elements as well as the operation of thedisclosed embodiments will become more apparent in light of thefollowing description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of a wheel assembly, in accordancewith various embodiments;

FIGS. 2A and 2B illustrate perspective views of a hybrid torque bar, inaccordance with various embodiments;

FIG. 2C illustrates a perspective view of a base portion of a hybridtorque bar, in accordance with various embodiments;

FIG. 2D illustrates a cross-sectional view of the hybrid torque bar ofFIG. 2A as viewed from the line 2D-2D in FIG. 2A, in accordance withvarious embodiments;

FIG. 2E illustrates a cross-sectional view of the hybrid torque bar ofFIG. 2A as viewed from the line 2E-2E in FIG. 2A, in accordance withvarious embodiments;

FIG. 3A illustrates a perspective view of a hybrid torque bar, inaccordance with various embodiments;

FIG. 3B illustrates a cross-sectional view of the hybrid torque bar ofFIG. 3A as viewed from the line 3B-3B in FIG. 3A, in accordance withvarious embodiments;

FIGS. 4A and 4B illustrate a method of making a hybrid torque bar, inaccordance with various embodiments; and

FIGS. 5A, 5B, 5C, and 5D illustrate a cross member of hybrid torque bar,in accordance with various embodiments.

The subject matter of the present disclosure is particularly pointed outand distinctly claimed in the concluding portion of the specification. Amore complete understanding of the present disclosure, however, may bestbe obtained by referring to the detailed description and claims whenconsidered in connection with the drawing figures, wherein like numeralsdenote like elements.

DETAILED DESCRIPTION

The detailed description of exemplary embodiments herein makes referenceto the accompanying drawings, which show exemplary embodiments by way ofillustration. While these exemplary embodiments are described insufficient detail to enable those skilled in the art to practice theexemplary embodiments of the disclosure, it should be understood thatother embodiments may be realized and that logical changes andadaptations in design and construction may be made in accordance withthis disclosure and the teachings herein without departing from thespirit and scope of the disclosure. Thus, the detailed descriptionherein is presented for purposes of illustration only and not oflimitation.

Surface cross hatching lines may be used throughout the figures todenote different parts but not necessarily to denote the same ordifferent materials. Throughout the present disclosure, like referencenumbers denote like elements. Accordingly, elements with like elementnumbering may be shown in the figures, but may not necessarily berepeated herein for the sake of clarity.

As used herein, “distal” refers to the direction outward, or generally,away from a reference component. As used herein, “proximate” refers to adirection inward, or generally, towards the reference component.

As used herein, the term “additive manufacturing” encompasses any methodor process whereby a three-dimensional object is produced by creation ofa substrate or material, such as by addition of successive layers of amaterial to an object to produce a manufactured product that has anincreased mass or bulk at the end of the additive manufacturing processas compared to the beginning of the process. In contrast, traditional(i.e., non-additive) manufacturing by machining or tooling typicallyrelies on material removal or subtractive processes, such as cutting,machining, extruding, turning, drilling, grinding, stamping, and/or thelike, to produce a final manufactured object that has a decreased massor bulk relative to the starting workpiece. Other traditional,non-additive manufacturing methods include forging or casting, such asinvestment casting, which utilizes the steps of creating a form, makinga mold of the form, and casting or forging a material (such as metal)using the mold. As used herein, the term “additive manufacturing” shouldnot be construed to encompass a joining of previously formed objects.

A variety of additive manufacturing technologies are commerciallyavailable. Such technologies include, for example, fused depositionmodeling, polyjet 3D printing, electron beam freeform fabrication,direct metal laser sintering, electron-beam melting, selective lasermelting, selective heat sintering, selective laser sintering,stereolithography, multiphoton photopolymerization, and digital lightprocessing. These technologies may use a variety of materials assubstrates for an additive manufacturing process, including variousplastics and polymers, metals and metal alloys, ceramic materials, metalclays, organic materials, and the like. Any method of additivemanufacturing and associated compatible materials, whether presentlyavailable or yet to be developed, are intended to be included within thescope of the present disclosure.

Conventional torque bars are generally formed into the desired shapeusing traditional manufacturing methods, such as casting, forging, orsubtractive manufacturing. Such techniques tend to limit the potentialgeometries of the torque bars and increase material waste, resulting intorque bars of increased weight and greater cost. Hybrid torque bars ofthe present disclosure, in various embodiments, include a firstcomponent (e.g., a base portion) formed using a traditional,non-additive manufacturing technique, and a second component (e.g., arail or a pin) formed using an additive manufacturing technique. Formingone or more components of the hybrid torque bars using an additivemanufacturing technique tends to allow for geometries that decrease anoverall weight of the hybrid torque bar, while reducing waste material.Furthermore, additive manufacturing techniques can enable designs,features, and structures, which could not otherwise be produced throughconventional manufacturing. For example, in various embodiments,additive manufacturing techniques may be employed to make hybrid torquebars having hollow sections and lattice structures, graded materialcompositions, and other multi-functional behavior (e.g., wear resistancein some locations and thermal stability or increased conductivity inother locations). Design methods, including topology optimization,utilize numerical optimization methods to assist in selection of adesign for the structural components, by locating material within adesign/structure based on performance criteria (e.g., structural loads,thermal loads, etc.). These designs can be organic inshape/design/structure, and may not be capable of fabrication viatraditional methods due to their high complexity. Additive manufacturingcan enable fabrication of these complex designs within hybrid torquebars.

In various embodiments, additive manufacturing techniques may also beemployed to form a coating or coatings (e.g., a wear resistant coating)along an exterior surface of one or more components of the hybrid torquebar. In this regard, additive manufacturing can create a gradienttransition into the coating, which tends to decrease a likelihood ofseparation or delaminating of the coating from the underlying torque barcomponent.

With reference to FIG. 1, a wheel assembly 100 is illustrated inaccordance with various embodiments. Wheel assembly 100 may comprise aninboard wheel half 102 and an outboard wheel half 104. Inboard wheelhalf 102 includes a radially extending portion 106. Radially extendingportion 106 may be located proximate outboard wheel half 104 and mayreceive fasteners 107 configured to secure outboard wheel half 104 toinboard wheel half 102. Fastener 107 may comprise a bolt, screw, rivet,pin, clip, or other suitable securement mechanism.

Wheel assembly 100 may further comprise a plurality of torque bars 110.Torque bars 110 may be located circumferentially along a radially inwardsurface of inboard wheel half 102. In various embodiments, torque bars110 are oriented parallel to an axis of rotation 112 of wheel assembly100. Torque bars 110 may be configured to engage a brake assemblydisposed within wheel assembly 100.

Torque bars 110 may be coupled to inboard wheel half 102. For example,torque bars 110 may be coupled to inboard wheel half 102 via a fastener116. Fastener 116 may comprise a bolt, screw, rivet, pin, clip, or othersuitable securement mechanism. A pin 120 of torque bar 110 may belocated in radially extending portion 106 of inboard wheel half 102. Forexample, radially extending portion 106 of inboard wheel half 102 maydefine a receptacle or orifice 118 configured to receive pin 120. Invarious embodiments, receptacle 118 may comprise a pin or stud overwhich an opening 122 (with momentary reference to FIG. 2A) in the end ofpin 120 slides.

With reference to FIGS. 2A and 2B, a torque bar 110 is illustrated, inaccordance with various embodiments. Torque bar 110 includes a baseportion 124, an attachment flange 130 formed on one end of base portion124, and pin 120 formed on the opposite end of base portion 124. Torquebar 110 further includes rail 136 and 138. Torque bar 110 is a hybridtorque bar. As used herein, a “hybrid torque bar” refers to a torque barhaving at least one component (e.g., pin 120, attachment flange 130,and/or rails 136 and 138) formed using an additive manufacturingtechnique, for example, wire arc additive manufacturing or electron beamadditive manufacturing, and at least one component (e.g., base portion124) formed using a non-additive manufacturing technique, for example,forging, extrusion, machining, casting, stamping, or subtractivemanufacturing.

Referring to FIG. 2C, base portion 124 of torque bar 110 is illustrated,in accordance with various embodiments. Base portion 124 may comprise agenerally rectangular shape including a first end 126, a second end 128opposite first end 126, and opposing surfaces 127 and 129 extending fromfirst end 126 to second end 128. Base portion 124 may be formed using amanufacturing process that employs non-additive manufacturingtechniques. For example, base portion 124 may be formed by forging,extrusion, machining, casting, stamping, subtractive manufacturing,and/or other suitable non-additive manufacturing technique.

Base portion 124 is formed from a metal alloy 125. In variousembodiments, base portion 124 may be made from a nickel-based alloyconforming to the unified numbering system standard (UNS) N07718 andcomprising, by wt %, between 17% and 21% chromium, between 2.8% and 3.3%molybdenum, between 50% and 55% nickel, and between 4.75% and 5.5%niobium, and which is available under the trade name INCONEL® 718,available from the Special Metals Corporation of Huntington, W. Va.,USA. As another example, base portion 124 may be made from aprecipitation-hardened chromium-nickel-aluminum-based stainless steelalloy conforming to the UNS S17700, and which is comprised of, by wt %,a maximum of 0.09% carbon, a maximum of 1% manganese, a maximum of 1%silicon, between 16% and 18% chromium, between 6.5% and 7.75% nickel,between 0.75% and 1.5% aluminum, a maximum of 0.04% phosphorus, amaximum of 0.03% sulfur, and a remaining balance of iron, and which isavailable under the trade name 17-7 PH®, available from AK Steel of WestChester, Ohio, USA). As yet another example, base portion 124 maycomprise a nickel-cobalt-based alloy conforming to the UNS N13100 andcomprising, by wt %, a maximum of between 0.15% and 0.2% carbon, between8% and 11% chromium, between 13% and 17% cobalt, between 2% and 4%molybdenum, between 4.5% and 5% titanium, between 5% and 6% aluminum,and a remaining balance of nickel, and which is available under thetrade name IN® 100, available from the Metal Tek International ofWaukesha, Wis., USA.

Base portion 124 may also be made from a nickel-based super alloy, amartensitic chromium-nickel-copper precipitation hardening stainlesssteel alloy conforming to UNS S17400, a nickel-chromium-molybdenum lowalloy steel conforming to UNS G86200, a chromium-nickel-molybdenum lowalloy steel conforming to UNS G43400, a low alloy, heat resistant steelconforming to UNS K23015, or any other suitable material. The relativelysimple geometry (e.g., the rectangular shape) of base portion 124 tendsto reduce manufacturing time and product waste.

Referring to FIGS. 2A and 2C, pin 120 may be formed extending axially(i.e., in the direction of the x-axis of FIG. 2A and generally parallelto axis of rotation 112 in FIG. 1) from first end 126 of base portion124. In various embodiments, pin 120 is formed using a manufacturingprocess that employs an additive manufacturing technique. For example,pin 120 may be formed by wire arc additive manufacturing, electron beamadditive manufacturing, or other suitable additive manufacturingtechnique. In this regard base portion 124 may be formed by forging,extrusion, casting, and/or machining, and pin 120 may be formed byadditive manufacturing.

Employing additive manufacture to form pin 120 allows the material(s)and/or design of pin 120 to be optimized for wear resistance, thermalprotection, thermal conduction, load strength, bending resistance,and/or improved vibration damping characteristics. In this regard, thematerial (e.g., the metal alloy) of pin 120 may be selected and/orvaried across pin 120 to reduce wear, tune stiffness, reduce weight,tune bending resistance, improve vibration characteristics, increasethermal resistance, and/or protect against oxidation. For example, aportion of pin 120 that experiences increased bending loads may comprisea metal alloy having an increased resistance to bending as compared tothe metal alloy of a portion of pin 120 that does not experienceincreased bending loads during use. In this regard, forming components(e.g., pin 120, rails 136, 138, etc.) of hybrid torque bar 110 usingadditive manufacturing may enable multi-functional optimization on alocation-by-location basis.

FIG. 2D illustrates a cross-sectional view of pin 120 taken along theline 2D-2D in FIG. 2A. In various embodiments, a coating 155, forexample, a wear resistance coating, a thermal resistance coating, acorrosion resistance coating, or a combination of two or more coatingtypes may be formed proximate an exterior of pin 120 using additivemanufacturing. Stated differently, during formation of pin 120, coating155 may be deposited using additive manufacturing and may form, anexterior portion 152 of pin 120. Coating 155 may be formed using a metalalloy 153. In various embodiments, metal alloy 153 may comprise a wearresistant coating material. In various embodiments, the wear resistantcoating material may comprise a metal carbide, for example, a tungstencarbide (e.g., tungsten carbide cobalt, tungsten carbide cobaltchromium), a chromium carbide, a vanadium carbide, or the like. Invarious embodiments, the wear resistant coating material may comprise anickel-based alloy, (e.g., a nickel sulfur alloy, a nickel phosphorusalloy, a nickel polytetrafluoroethylen (PTFE) composite alloy, etc.), anickel-based super alloy, or the like.

In various embodiments, pin 120 may include an intermediate portion 154extending between an interior portion 150 of pin 120 and exteriorportion 152. Interior portion 150 of pin 120 may be formed using a metalalloy 151. In various embodiments, metal alloy 151 may comprise the sameor a similar material to metal alloy 125 of base portion 124. In variousembodiments, intermediate portion 154 may comprise a metal alloy 156.Metal alloy 156 may comprise a wear resistant coating material. Invarious embodiments, a thickness of intermediate portion 154 and metalalloy 156 may be different from a thickness of exterior portion 152 andmetal alloy 153. In various embodiments, exterior portion 152 may form atopcoat over intermediate portion 154. For example, intermediate portion154 may comprise a metal carbide and exterior portion 152 may comprise anickel-based alloy topcoat formed over intermediate portion 154. Invarious embodiments, intermediate portion 154 may comprise a metalcarbide or a nickel-based alloy and exterior portion 152 may comprise anickel PTFE composite alloy topcoat formed over intermediate portion154.

In various embodiments, intermediate portion 154 may form a gradienttransition between metal alloy 151 of interior portion 150 and metalalloy 153 of exterior portion 152. The gradient transition (i.e.,intermediate portion 154) may have a percent by weight of metal alloy153 defined by a smooth function of position along the gradienttransition. The gradient transition may also have a smooth function ofpercent by weight of the metal alloy 151 of interior portion 150relative to position along the gradient transition. For example, thetransition from metal alloy 151 of interior portion 150 to metal alloy153 of exterior portion 152 may be linear, logarithmic, exponential,quadratic, or any other smoothly defined and continuous function. Thepercent by weight of metal alloy 153 may thus increase as the gradienttransition goes from interior portion 150 to exterior portion 152.

In various embodiments, metal alloy 151 comprises a first percentage(e.g., 0%-20%, 0%-10%, or 0%-5%) by weight of a wear resistant coatingmaterial (e.g., a metal carbide, a nickel-based alloy, a nickel-basedsuper alloy), metal alloy 153 comprises a second percentage (e.g.,60%-99%, 70%-95%, or 80%-95%) by weight of the wear resistant coatingmaterial, and intermediate portion 154 (i.e., the gradient transition)comprises an increasing percentage by weight of the wear resistantcoating material. For example, the percentage by weight of the wearresistant coating material (e.g., the percent by weight of the metalcarbide) may increase in intermediate portion 154 between interiorportion 150 and exterior portion 152. The gradient transition ofintermediate portion 154 may increase an adhesion and/or bondingstrength of metal alloy 153 and exterior portion 152 to metal alloy 151and interior portion 150. In this regard, intermediate portion 154forming a gradient transition may reduce the stress caused bydifferences in the coefficient of thermal expansion (CTE) between metalalloy 153 and metal alloy 151.

Returning to FIG. 2A, torque bar 110 further comprises rail 136 and rail138. In various embodiments, rails 136 and 138 are parallel to oneanother and extend axially (i.e., in the direction of the x-axis andgenerally parallel to axis of rotation 112 in FIG. 1) between first end126 and second end 128 of base portion 124. Rails 136 and 138 may extendradially (i.e., in a direction generally orthogonal to the x-axis inFIG. 2A and axis of rotation 112 in FIG. 1) away from surface 127 ofbase portion 124.

In various embodiments, rails 136 and 138 may be formed using amanufacturing process that employs an additive manufacturing technique.For example, rails 136 and 138 may be formed by wire arc additivemanufacturing, electron beam additive manufacturing, or other suitableadditive manufacturing technique. In this regard, base portion 124 maybe formed by forging, extrusion, casting, and/or machining, and rails136 and 138 may be formed by additive manufacturing.

Employing additive manufacture to form rails 136 and 138 allows thematerial(s) and/or design of rails 136 and 138 to be optimized for wearresistance, thermal protection, thermal conduction, load strength,bending resistance, and/or improved vibration damping characteristics.In this regard, the material (e.g., the metal alloy) of rails 136 and138 may be selected and/or varied across rails 136 and 138 to reducewear, tune stiffness, reduce weight, tune bending resistance, improvevibration characteristics, increase thermal resistance, and/or protectagainst oxidation. For example, with reference to FIG. 2B, in variousembodiments, a portion 142 of rail 138 may comprise a metal alloy 143,and a portion 144 of rail 138 may comprise a metal alloy 146 that isdifferent from metal alloy 143. Stated differently, portion 142 may beformed by depositing metal alloy 143 over base portion 124 using wirearc or electron beam additive manufacturing, and portion 144 may beformed by depositing metal alloy 146. In various embodiments, portion142 may comprise a material having a greater heat resistance (i.e.,higher melting point), a greater tensile strength, and/or a greatercreep resistance as compared to the material of portion 144. In variousembodiments, portion 142 may comprise a material having a differentthermal conductivity as compared to the material of portion 144 toprovide variable heat conduction during braking. In various embodiment,the transition between portion 142 and portion 144 may be a gradienttransition. In this regard, forming components (e.g., rails 136, 138,pin 120, etc.) of hybrid torque bar 110 using additive manufacturing mayenable multi-functional optimization on a location-by-location basis.While rail 138 is shown having axially adjacent portions of varyingmaterials, it should be understood that rail 138 may be formed havingradially adjacent, circumferentially adjacent, and/or diagonallyadjacent portions of varying materials.

FIG. 2E illustrates a cross-sectional view of torque bar 110 taken alongthe line 2E-2E in FIG. 2A. In various embodiments, a coating 165, forexample, a wear resistance coating, a thermal resistance coating, acorrosion resistance coating, or a combination of two or more coatingtypes may be formed proximate an exterior of rails 136 and 138 usingadditive manufacturing. Stated differently, during formation of rails136 and 138, coating 165 may be deposited using additive manufacturingand may form an exterior portion 162 of rails 136 and 138. Coating 165may be formed using a metal alloy 163. In various embodiments, metalalloy 163 may be the same as metal alloy 153 of pin 120 (with momentaryreference to FIG. 2D). In this regard, metal alloy 163 may comprise awear resistant coating material, for example, a metal carbide, anickel-based alloy, a nickel-based super alloy, or the like.

In various embodiments, rails 136, 138 may include an intermediateportion 164 extending between an interior portion 160 of rails 136, 138and exterior portion 162. In various embodiments, intermediate portion164 may comprise a metal alloy 166, similar to metal alloy 156 in FIG.2D. In various embodiments, intermediate portion 164 may comprise agradient transition, similar intermediate portion 154 in FIG. 2D.Interior portion 160 of rails 136 and 138 may be formed using a metalalloy 161. In various embodiments, metal alloy 161 may comprise the sameor a similar material to metal alloy 125 of base portion 124 and/or thesame or a similar material to metal alloy 151 of pin 120 (with momentaryreference to FIG. 2D).

Returning to FIG. 2A, in various embodiments, torque bar 110 may furthercomprise a cross member 140 extending between rail 136 and rail 138. Invarious embodiments, cross member 140 may be formed using amanufacturing process that employs an additive manufacturing technique.In various embodiments, cross member 140 may be formed using the samematerial (i.e., metal alloy) as base portion 124. In variousembodiments, a wear resistance coating, a thermal resistance coating, acorrosion resistance coating, or a combination of two or more coatingtypes may be formed proximate an exterior of cross member 140 usingadditive manufacturing. An intermediate portion, which may comprise agradient transition, similar to intermediate portion 154 in FIG. 2D, mayextend between an interior portion and the exterior of cross member 140.

In various embodiments, using additive manufacturing to form crossmember 140, may allow cross member 140 to be formed having a hollow orhoneycomb geometry. Referring to FIG. 5A, a perspective view of crossmember 140 is illustrated. Cross member 140 includes a surface 320oriented generally way from base portion 124, with momentary referenceto FIG. 2A. Surface 320 is generally parallel the x-axis. Cross member140 further includes opposing surfaces 321 and 322. Surfaces 321 and 322extend between base portion 124 (with momentary reference to FIG. 2A)and surface 320, and are generally orthogonal to the x-axis. FIG. 5Billustrates a cross-section view of cross member 140 taken along theline 5B-5B in FIG. 5A. In various embodiments, cross member 140 mayinclude and define openings 324. In various embodiments, one or moreopenings 324 is formed partially through cross member 140 in the axialdirection (i.e., in the direction of the x-axis), such that a portion ofcross member 140 remains between opening 324 and surface 321 and/orbetween opening 324 and surface 322. In various embodiments, one or moreopenings 324 may extend completely through cross member 140 in the axialdirection, such that opening 324 extends from surface 321 to surface322. While openings 324 are illustrated having a generally rectangulargeometry, it should be understood that openings 324 may be formed havingan oval, circular, hexagonal, polygonal, or any other shape orcombination of shapes.

FIG. 5C illustrates a perspective view of a cross member 340 includingand defining openings 342. In various embodiments, cross member 340 maybe formed in hybrid torque bar 110 in place of cross member 140 (withmomentary reference to FIG. 2A). Openings 342 may extend in a radialdirection, generally orthogonal to the axial direction (i.e., in thedirection of the y-axis). In various embodiments, one or more openings342 may extend completely through cross member 340 in the radialdirection, such that the opening 342 extends through surface 344 ofcross member 340. In various embodiments, one or more openings 342 maybe formed partially through cross member 340 in the radial direction,such that a portion of cross member 340 remains between the opening 342and surface 344 of cross member 340. While openings 342 are illustratedhaving a generally square geometry, it should be understood thatopenings 342 may be formed having an oval, circular, hexagonal,polygonal, or any other shape or combination of shapes.

FIG. 5D illustrates a perspective view of a cross member 350 includingand defining openings 352. In various embodiments, cross member 350 maybe formed in hybrid torque bar 110 in place of cross member 140 (withmomentary reference to FIG. 2A). Openings 352 may extend in a radialdirection, generally orthogonal to the axial direction (i.e., in thedirection of the y-axis). Openings 352 may be elongated in thecircumferential direction (i.e., in the direction of the z-axis), suchthat the openings 352 extend a greater distance in the circumferentialdirection as compared to the axial direction. Stated differently, adimension of opening 352 as measured along the z-axis is greater than adimension of opening 352 as measured along the x-axis. In variousembodiments, one or more openings 352 may extend completely throughcross member 350 in the radial direction, such that the opening 352extends through a surface 354 of cross member 350. In variousembodiments, one or more openings 352 may be formed partially throughcross member 350 in the radial direction, such that a portion of crossmember 350 remains between the opening 352 and surface 354 of crossmember 350. While openings 352 are illustrated having a generallyrectangular geometry, it should be understood that openings 342 may beformed having an oval, circular, hexagonal, polygonal, or any othershape or combination of shapes.

Referring to FIG. 2B, in various embodiments, torque bar 110 furtherincludes attachment flange 130. Attachment flange 130 may be formedextending from second end 128 of base portion 124. Attachment flange 130may define a mounting hole 132. Mounting hole 132 may be configured toreceive fastener 116, with momentary reference to FIG. 1 and coupletorque bar 110 to inboard wheel half 102.

In various embodiments, attachment flange 130 is formed using amanufacturing process that employs an additive manufacturing technique.Attachment flange 130 comprises a metal alloy 148. In variousembodiments, metal alloy 148 may be the same as or similar to the metalalloy used to form base portion 124. In various embodiments, a wearresistance coating, a thermal resistance coating, a corrosion resistancecoating, or a combination of two or more coating types may be formedproximate an exterior of attachment flange 130 using additivemanufacturing. An intermediate portion, which may comprise a gradienttransition, similar to intermediate portion 154 in FIG. 2D, may extendbetween an interior portion and the exterior of attachment flange 130.In various embodiments, using additive manufacturing to form attachmentflange 130, may allow attachment flange 130 to be formed having ahoneycomb structure. Stated differently, a cross-section of attachmentflange 130 may comprise a honeycomb geometry.

Referring to FIG. 3A, a torque bar 210 is illustrated, in accordancewith various embodiments. Torque bar 210 comprises a base portion 224and a pin 220 extending from a first end 226 of base portion 224. Torquebar 210 further comprises rails 236 and 238 which extend between firstend 226 and a second end 228 of base portion 224. In variousembodiments, torque bar 210 may be employed in wheel assembly 100 inplace of a torque bar 110 (with momentary reference to FIG. 1).

With combined reference to FIGS. 3A and 3B, in various embodiments,torque bar 210 comprise an “I” shaped cross-section. A portion 236 a ofrail 236 extends from surface 227 of base portion 124 in a firstdirection and a portion 236 b of rail 236 extend from surface 229 ofbase portion in a second direction opposite the first direction.Similarly, a portion 238 a of rail 238 extends from surface 227 in thefirst direction and a portion 238 b of rail 238 extends from surface 229in the second direction. In various embodiments, an attachment flange230 may extend radially, in the first direction from surface 227 of baseportion 224. Attachment flange 230 may define a mounting hole 232. Invarious embodiments, attachment flange 230 may be located between secondend 228 and first end 226 of base portion 224.

Torque bar 210 is a hybrid torque bar. At least one component (e.g., pin220, attachment flange 230, and/or rails 236 and 238) of torque bar 210is formed using an additive manufacturing technique, for example, wirearc additive manufacturing or electron beam additive manufacturing, andat least one component (e.g., base portion 224) is formed using anon-additive manufacturing technique, for example, forging, extrusion,machining, casting, stamping, or subtractive manufacturing. Usingadditive manufacturing to form rails 236 and 238 may allow rails 236 and238 to include (i.e., define) voids or hollow portions 237. In thisregard, rails 236 and 238 may comprise a lattice structure. Hollowportions 237 may decrease a weight and/or a material cost of torque bar210. The location of hollow portions 237 may be selected using topologyoptimization and performance criteria (e.g., structural loads, thermalloads, etc.) experienced by rails 236 and 238. In various embodiments,using additive manufacturing to form attachment flange 230, may allowattachment flange 230 to be formed having a hollow portions, similar tohollow portion 237, or a honeycomb structure.

In various embodiments, a coating 240, for example, a wear resistancecoating, a thermal resistance coating, a corrosion resistance coating,or a combination of two or more coating types may be formed proximate anexterior of torque bar 210 using additive manufacturing. Stateddifferently, coating 240 may be deposited using additive manufacturingand may form, at least a portion of, an exterior surface of base portion224, pin 220, attachment flange 230, and/or rails 236 and 238. Invarious embodiments, rails 236 and 238 may include an intermediateportion 254 and an exterior portion 252. Intermediate portion 254 mayextend between an interior portion 250 of rails 236 and 238 and exteriorportion 252. In this regard, exterior portion 252 forms the exteriorportion of rails 236 and 238. Intermediate portion 254 may also extendbetween base portion 224 and exterior portion 252, and/or betweenexterior portion 252 and interior portions of pin 220 and attachmentflange 230. In various embodiments, exterior portion 252 may comprise ametal alloy 253, and intermediate portion 254 may comprise a metal alloy256. Metal alloys 253 and 256 may comprise wear resistant coatingmaterial, for example, a metal carbide, a nickel-based alloy, anickel-based super alloy, or the like. In various embodiments, athickness of intermediate portion 254 and metal alloy 256 may bedifferent from a thickness of exterior portion 252 and metal alloy 253.In various embodiments, exterior portion 252 may form a topcoat overintermediate portion 254. For example, intermediate portion 254 maycomprise a metal carbide and exterior portion 252 may comprise anickel-based alloy topcoat formed over intermediate portion 254. Invarious embodiments, intermediate portion 254 may comprise a metalcarbide or nickel-based alloy, and exterior portion 252 may comprise anickel PTFE composite alloy topcoat formed over intermediate portion254.

In various embodiments, intermediate portion 254 may form a gradienttransition between metal alloy 253 and a metal alloy 251 at the interiorportion 250 of rails 236, 238, and between metal alloy 253 and a metalalloy 225 of base portion 224. In various embodiments, metal alloy 251may be the same or similar to metal alloy 225. A gradient transition mayalso be formed between metal alloy 253 and a metal alloy at the interiorof pin 220 and attachment flange 230. The gradient transition (i.e.,intermediate portion 254) may have a percent by weight of metal alloy253 defined by a smooth function of position along the gradienttransition. The gradient transition may also have a smooth function ofpercent by weight of metal alloy 251 and/or metal alloy 225 relative toposition along the gradient transition. For example, the transition frommetal alloy 251 to metal alloy 253 may be linear, logarithmic,exponential, quadratic, or any other smoothly defined and continuousfunction. The percent by weight of metal alloy 253 may thus increase asthe gradient transition goes from interior portion 250 to exteriorportion 252 and from base portion 224 to exterior portion 252.

FIGS. 4A and 4B illustrate a method 300 of making a hybrid torque tubefor a wheel assembly, in accordance with various embodiments. Method 300may comprise forming a base portion using a first manufacturing process(step 302). In various embodiments, the first manufacturing processcomprises forging, extrusion, casting, machining and/or subtractivemanufacturing. Method 300 may further comprise forming a pin extendingfrom a first end of the base portion (step 304). In various embodiments,step 302 includes forming the base portion using a non-additivemanufacturing technique, for example, forging, extrusion, casting,machining, and step 304 includes forming the pin using an additivemanufacturing technique, for example, wire arc or electron beam additivemanufacturing.

In various embodiments, forming the pin may include forming a coatinglocated at an exterior of the pin. In this regard, in variousembodiments, step 304 may comprising forming an interior portion of thepin using a first metal alloy (step 304 a), forming an intermediateportion over the interior portion (step 304 b), and forming an exteriorportion of the pin using a second metal alloy (step 304 c). In variousembodiments, the intermediate portion may form a gradient transitionbetween the interior portion and exterior portion. Steps 304 a, 304 b,and 304 c may be performed using additive manufacturing. In variousembodiments, the first metal alloy may comprise a first percentage byweight of a wear resistant coating material, the second metal alloy maycomprise a second percentage by weight of the wear resistant coatingmaterial, and the gradient transition (i.e., intermediate portion) maycomprise an increasing percentage by weight of the wear resistantcoating material. In various embodiments, the wear coating material maycomprise a metal carbide, a nickel-based alloy, a nickel-based superalloy, and/or combinations thereof.

Method 300 further comprises forming an attachment flange extending fromthe base portion (step 306). In various embodiments, step 302 includesforming the base portion using a non-additive manufacturing technique,for example, forging, extrusion, casting, machining, and step 306includes forming the attachment flange using an additive manufacturingtechnique, for example, wire arc or electron beam additivemanufacturing.

In various embodiments, forming the attachment flange may includeforming a coating located at an exterior of the attachment flange. Inthis regard, in various embodiments, step 306 may comprising forming aninterior portion of the attachment flange using a first metal alloy(step 306 a), forming an intermediate portion over the interior portion(step 306 b), and forming an exterior portion of the attachment flangeusing a second metal alloy (step 306 c). In various embodiments, theintermediate portion may form a gradient transition between the interiorportion and exterior portion. Steps 306 a, 306 b, and 306 c may beperformed using additive manufacturing. In various embodiments, thefirst metal alloy may comprise a first percentage by weight of a wearresistant coating material, the second metal alloy may comprise a secondpercentage by weight of the wear resistant coating material, and thegradient transition may comprise an increasing percentage by weight ofthe wear resistant coating material.

Method 300 further includes forming a rail extending between the firstend of the base portion and a second end of the base portion oppositethe first end (step 308). In various embodiments, step 302 includesforming the base portion using a non-additive manufacturing technique,for example, forging, extrusion, casting, machining, and step 308includes forming the rail using an additive manufacturing technique, forexample, wire arc or electron beam additive manufacturing.

In various embodiments, forming the rail may include forming a coatinglocated at an exterior of the rail. In this regard, in variousembodiments, step 308 may comprise forming an interior portion of therail using a first metal alloy (step 308 a), forming an intermediateportion over the interior portion (step 308 b), and forming an exteriorportion of the rail using a second metal alloy (step 308 c). In variousembodiments, the intermediate portion may form a gradient transitionbetween the interior portion and exterior portion. Steps 308 a, 308 b,and 308 c may be performed using additive manufacturing. In variousembodiments, the first metal alloy may comprise a first percentage byweight of a wear resistant coating material, the second metal alloy maycomprise a second percentage by weight of the wear resistant coatingmaterial, and the intermediate portion may comprise an increasingpercentage by weight of the wear resistant coating material. In variousembodiments, the coating may be formed over the base portion of thetorque bar.

Benefits, other advantages, and solutions to problems have beendescribed herein with regard to specific embodiments. Furthermore, theconnecting lines shown in the various figures contained herein areintended to represent exemplary functional relationships and/or physicalcouplings between the various elements. It should be noted that manyalternative or additional functional relationships or physicalconnections may be present in a practical system. However, the benefits,advantages, solutions to problems, and any elements that may cause anybenefit, advantage, or solution to occur or become more pronounced arenot to be construed as critical, required, or essential features orelements of the disclosure.

The scope of the disclosure is accordingly to be limited by nothingother than the appended claims, in which reference to an element in thesingular is not intended to mean “one and only one” unless explicitly sostated, but rather “one or more.” It is to be understood that unlessspecifically stated otherwise, references to “a,” “an,” and/or “the” mayinclude one or more than one and that reference to an item in thesingular may also include the item in the plural. All ranges and ratiolimits disclosed herein may be combined.

Moreover, where a phrase similar to “at least one of A, B, and C” isused in the claims, it is intended that the phrase be interpreted tomean that A alone may be present in an embodiment, B alone may bepresent in an embodiment. C alone may be present in an embodiment, orthat any combination of the elements A, B and C may be present in asingle embodiment; for example, A and B, A and C. B and C. or A and Band C.

The steps recited in any of the method or process descriptions may beexecuted in any order and are not necessarily limited to the orderpresented. Furthermore, any reference to singular includes pluralembodiments, and any reference to more than one component or step mayinclude a singular embodiment or step. Elements and steps in the figuresare illustrated for simplicity and clarity and have not necessarily beenrendered according to any particular sequence. For example, steps thatmay be performed concurrently or in different order are illustrated inthe figures to help to improve understanding of embodiments of thepresent disclosure.

Any reference to attached, fixed, connected or the like may includepermanent, removable, temporary, partial, full and/or any other possibleattachment option. Additionally, any reference to without contact (orsimilar phrases) may also include reduced contact or minimal contact.Surface shading lines may be used throughout the figures to denotedifferent parts or areas but not necessarily to denote the same ordifferent materials. In some cases, reference coordinates may bespecific to each figure.

Systems, methods and apparatus are provided herein. In the detaileddescription herein, references to “one embodiment”, “an embodiment”,“various embodiments”, etc., indicate that the embodiment described mayinclude a particular feature, structure, or characteristic, but everyembodiment may not necessarily include the particular feature,structure, or characteristic. Moreover, such phrases are not necessarilyreferring to the same embodiment. Further, when a particular feature,structure, or characteristic is described in connection with anembodiment, it is submitted that it is within the knowledge of oneskilled in the art to affect such feature, structure, or characteristicin connection with other embodiments whether or not explicitlydescribed. After reading the description, it will be apparent to oneskilled in the relevant art(s) how to implement the disclosure inalternative embodiments.

Furthermore, no element, component, or method step in the presentdisclosure is intended to be dedicated to the public regardless ofwhether the element, component, or method step is explicitly recited inthe claims. No claim element is intended to invoke 35 U.S.C. 112(f)unless the element is expressly recited using the phrase “means for.” Asused herein, the terms “comprises”, “comprising”, or any other variationthereof, are intended to cover a non-exclusive inclusion, such that aprocess, method, article, or apparatus that comprises a list of elementsdoes not include only those elements but may include other elements notexpressly listed or inherent to such process, method, article, orapparatus.

What is claimed is:
 1. A hybrid torque bar for a wheel assembly, thehybrid torque bar comprising: a base portion; a pin extending from afirst end of the base portion; and a first rail extending between thefirst end of the base portion and a second end of the base portionopposite the first end, wherein an interior portion of at least one ofthe pin or the first rail comprises a first metal alloy, an exteriorportion of the at least one of the pin or the first rail comprises asecond metal alloy, and an intermediate portion of the at least one ofthe pin or the first rail extends between the interior portion and theexterior portion.
 2. The hybrid torque bar of claim 1, wherein theintermediate portion forms a gradient transition between the first metalalloy and the second metal alloy, the gradient transition including apercent by weight of a wear resistant coating material defined by asmooth function of position along the gradient transition.
 3. The hybridtorque bar of claim 2, wherein the wear resistant coating materialcomprises at least one of a metal carbide, a nickel-based alloy, or anickel-based super alloy.
 4. The hybrid torque bar of claim 1, furthercomprising: a second rail extending between the first end of the baseportion and the second end of the base portion; and a cross memberextending between the first rail and the second rail, wherein the crossmember defines an opening.
 5. The hybrid torque bar of claim 1, whereina first portion of the first rail extends in a first direction, and asecond portion of the first rail extends in a second direction oppositethe first direction.
 6. The hybrid torque bar of claim 5, furthercomprising an attachment flange extending from the base portion in thefirst direction.
 7. The hybrid torque bar of claim 1, wherein the firstrail defines a hollow portion.
 8. A wheel assembly, comprising: a wheel;and a hybrid torque bar coupled to the wheel, the hybrid torque barcomprising a base portion; a pin extending from a first end of the baseportion; and a rail extending between the first end of the base portionand a second end of the base portion opposite the first end, wherein aninterior portion of at least one of the pin or the rail comprises afirst metal alloy, wherein an exterior portion of the at least one ofthe pin or the rail comprises a second metal alloy, and wherein anintermediate portion of the at least one of the pin or the rail extendsbetween the interior portion and the exterior portion.
 9. The wheelassembly of claim 8, wherein the wheel comprises an inboard wheel halfand an outboard wheel half, and wherein the pin is located in areceptacle defined by the inboard wheel half.
 10. The wheel assembly ofclaim 8, wherein the first metal alloy comprises a first percentage byweight of a wear resistant coating material, the second metal alloycomprises a second percentage by weight of the wear resistant coatingmaterial, and the intermediate portion comprises an increasingpercentage by weight of the wear resistant coating material.
 11. Thewheel assembly of claim 10, wherein the wear resistant coating materialcomprises at least one of a metal carbide, a nickel-based alloy, or anickel-based super alloy.
 12. A method of making a hybrid torque bar fora wheel assembly, comprising: forming a base portion using a firstmanufacturing process; forming a pin extending from a first end of thebase portion; forming an attachment flange extending from the baseportion; and forming a rail extending between the first end of the baseportion and a second end of the base portion opposite the first end,wherein at least one of the forming the attachment flange, the formingthe pin, or the forming the rail comprises using a second manufacturingprocess, the second manufacturing process comprising an additivemanufacturing technique.
 13. The method of claim 12, wherein the firstmanufacturing process comprises at least one of forging, extrusion,casting, machining, stamping, or subtractive manufacturing.
 14. Themethod of claim 12, further comprising forming at least one of theattachment flange, the pin, or the rail comprising a coating located atan exterior of the at least one of the attachment flange, the pin, orthe rail.
 15. The method of claim 14, wherein forming the at least oneof the attachment flange, the pin, or the rail comprising the coatingcomprises: forming an interior portion of the at least one of theattachment flange, the pin, or the rail using a first metal alloy;forming an exterior portion of the at least one of the attachmentflange, the pin, or the rail using a second metal alloy; and forming agradient transition extending between the interior portion and theexterior portion.
 16. The method of claim 15, wherein the first metalalloy comprises a first percentage by weight of a wear resistant coatingmaterial, the second metal alloy comprises a second percentage by weightof the wear resistant coating material, and the gradient transitioncomprises an increasing percentage by weight of the wear resistantcoating material.
 17. The method of claim 16, wherein the wear resistantcoating material comprises at least one or a metal carbide, anickel-based alloy, or a nickel-based super alloy.
 18. The method ofclaim 16, further comprising forming the gradient transition including apercent by weight of the wear resistant coating material defined by asmooth function of position along the gradient transition.
 19. Themethod of claim 18, wherein the smooth function of position comprises atleast one a linear function, a logarithmic function, an exponentialfunction, or a quadratic function.
 20. The method of claim 14, furthercomprising forming the coating extending over, at least a portion of, asurface of the base portion.